Taste and aroma are a tricky combination. A pungent, stinky cheese tastes much better than it smells, while a poorly made cup of coffee will still smell delicious wafting across the room. When we are forced to ingest bitter or unpleasant medicine we hold our nose to tamp down the flavor and when we are congested and stuffy food loses its inherent flavor when we consume it. This is because it is the odor molecules in food that give it its flavor.
Wine tasters are given lessons in how to evaluate flavors, to taste consciously. It’s an interesting skill and one that most people could benefit from learning more about. At a wine tasting the first evaluation is visual. Truthfully you can smell a great wine as soon as it is poured into the glass but we file that scent away for a moment while we absorb the appearance of the wine. We make judgments based on visual cues. For example an older red wine that is tinged with orange at the rim is probably past its peak, the flavors will be on the downward slope, becoming more delicate and ethereal rather than fruit forward and complex.
Next we smell the wine. We take a moment to swirl the glass to release additional volatile compounds. If we taste a wine that is too cold, we may cup our hands around the glass to warm it slightly, although that is a faux pas in the normal course of events. We evaluate the aromas, considering other familiar scents that they remind us of. Finally we sip, making a point of drawing oxygen in with the wine and swirling the mixture around in our mouths, loudly or softly depending upon our personalities, before swallowing and exhaling. The length that the flavor lingers in the mouth is directly related to the perceived quality of the wine. The process of oxygenating and agitating the liquid in our mouths allow more of the odorant molecules to rise up through our nasal passages. That final sigh stirs up the last of the volatile compounds and allows us to experience them without the distraction of the liquid and fully appreciate the flavors of the wine.
The tongue can only detect so many flavor components. Most people agree that the five flavors now are sweet, salty, sour, bitter and umami. The sensations in the mouth also determine temperature and irritation to the tongue and throat. The ability to perceive irritants is considered a chemical sense. It manifests as the sharp unpleasant reaction to ammonia or the tingle of heat from a chili. When food is presented to us the first thing we experience is usually the aroma. Even before the food is close enough to see clearly, in many cases we can smell it coming. Odor molecules travel through your nasal passage and mouth to your olfactory receptors, located at the top of your nasal passage. When you sinuses are congested the molecules can no longer reach these receptors and you lose your sense of smell.
For many animals smell is their strongest sense. It alerts them to danger, helps them locate food and then determines whether or not it is safe to eat, and detects pheromones in other animals. Although humans no longer need their sense of smell to survive, it is an integral sense in experiencing many of life’s pleasures.
Aromas are highly complex messages being decoded by our brains. We have millions of odor receptor cells with approximately 1000 different genes. Each type of odor receptor is specialized to identify a few specific scents. Each aroma is comprised of hundreds of different odorant molecules that each react with specific odor receptors. The pattern of receptors that is activated determines our perception of a scent. In 2004 Richard Axel and Lind B. Buck won the Nobel Prize in Physiology or Medicine for determining how the olfactory system works and proving that we can identify and form memories of over 10,000 different scents.
Aroma and memory are intrinsically tied together. It’s amazing how evocative a scent can be. The aroma of corn on the grill takes us to the beach and the smell of a turkey roasting in the oven brings Thanksgiving to mind. In the old restaurant Bouley in New York, David Bouley had racks of apples lining the entrance foyer of the restaurant. The smell immediately awakened and relaxed people even if they were unaware of what was happening. It was a clever use of aroma and design.
Scents are created as volatile compounds, which are organic compounds that have enough vapor pressure to evaporate into the air under normal conditions. Heat causes the compounds to evaporate more quickly, which is why hot foods tend to have more flavor than cold ones. Many of these volatile compounds can be distilled in the form of essential oils. Chefs are beginning to work with food grade essential oils in the kitchen to enhance the flavor of their food. Commercial food processors are beginning to explore the idea of scented packaging to boost sales. Modern technology in the form of virtual aroma synthesizers are gaining popularity to test drive new flavors because aroma attraction has proven to be an accurate indicator of flavor preference and testers do not suffer the same level of sensory fatigue as they do when tasting a variety of new flavors.
Interestingly there is a new piece of equipment available to chefs known as the Volcano Vaporizer. We were given the opportunity to use one to see how it could benefit our culinary exploits. The vaporizer uses hot air to gently heat ingredients to the point where the essential oils are released as vapor. This vapor can be captured by the chef and used to infuse other ingredients with flavor through aroma. But don’t worry, you don’t need fancy equipment to use aroma in your cooking. It’s already there in everything in your kitchen. You just need a little imagination to help make your diners sit up and notice it.
Lavender Scented Fluke
2 fluke filets, approximately 18 ounces/510 grams
4 ½ cups/1000 grams water
5 ½ tablespoons/50 grams fine sea salt
Freeze dried pineapple
Fleur de sel
Extra virgin olive oil (we like Manni)
Trim the fluke of bloodline and remove any bones. Cut each fillet lengthwise, down the center and remove the coarse sinew, which runs along the mid-line of the fish. Dissolve the salt in the water. Place the fluke in the brine for ten minutes. Remove the fluke from the brine and pat dry.
Turn the Volcano Vaporizer on at 266°F. Lay the fluke fillets on a small metal rack and place them in a zip top bag. Seal the bag almost completely, leaving a corner open to put the tube from the vaporizer. Fill the chamber of the vaporizer with lavender and insert the extension tube into the bag. Run lavender aroma into the bag for five minutes, then close the bag and refrigerate the fish. After 10 minutes in the refrigerator, pull the fish out and repeat the infusion process. Do this one more time, for 3 total infusions. You may have to add more lavender blossoms to the vaporizer. After the third infusion let the fish rest in the refrigerator for at least a half an hour.
Alternatively, if you do not have a vaporizer, wrap each filet in a layer of cheese cloth. Sprinkle lavender blossoms on the top and bottom of the cheese cloth and then wrap each filet in plastic wrap. Refrigerate the fish for 2 hours. Unwrap one filet and smell it. If the lavender has permeated the fish unwrap the rest of the fish, otherwise re-wrap and let infuse for another hour. Once the fish is infused with the aroma of lavender, unwrap and remove the plastic and the cheese cloth, re-wrap the fish, and store it in the refrigerator until ready to serve.
To serve, remove the fillets from the refrigerator and lay on a cutting board. On a bias, thinly slice the fluke and arrange the slices on plates. Use a microplane to grate freeze dried pineapple over the fish. Sprinkle the fish with fleur de sel and drizzle with olive oil.